Boa Constrictor Care Sheet
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The Basic Facts You Need To Know
The boa constrictor is a non-venomous, constricting (you'd never guess, huh?) snake. There are many different sub-species but the one most commonly seen on the market, and the one best advised for beginners, is the BCI (boa constrictor imperator), also known as the common boa constrictor. For more information on sub-species see www.boa-contrictors.com.
Before you consider getting this snake, bare in mind that you are looking at a pet that can grow up to 10ft long and live over 20 years. Not only will it need a large enclosure that will take up a considerable amount of your space but it also needs a specific environment that you will need to maintain for the rest of its life. There are also the vet bills to consider (is there a reptile vet near you?) and you are going to have to feed your snake dead rodents several times a month.
Boa constrictors won't eat salad, so if you can't handle this and/or don't have the time, space or money to house this reptile then please think again.
Enclosure Size and Type
For boa constrictors the appropriate enclosure size can be worked out as such:
total length of snake = length of vivarium + width of vivarium.
So for example a 6ft snake would be happy in a 4ft long x 2ft wide vivarium, where as an 8ft snake would require a 6ft long x 2ft wide vivarium.
4ft x 2ft is the absolute minimum floor space any adult boa should have, with 5ft x 2ft being a comfortable size for most specimens and 6ft x 2ft being ideal.
No matter what the size of the boa is, the vivarium should not be much less than 2ft high. Boas like to climb, especially when younger, so this extra height gives room for branches and shelves to be added and it also leaves a gap between any ceramic/incandescent heating source and the snake.
Note: Only one snake per vivarium!
There are many different vivarium types available for housing snakes: glass, wooden and plastic to name a few. Each have their own benefits and short comings.
Great for seeing the snake but, because glass is useless at holding in heat, once you start getting into larger sizes it will become almost impossible to maintain appropriate temperatures and seeing as most glass tanks come with mesh tops you will also find water vapour easily escapes, dropping your humidity. Glass tanks are NOT recommended for keeping large boas. Some snakes may also find it very stressful being so out in the open and viewable to all.
Plastic with a glass front
Great for cleaning, insulates heat better than glass and gives the snake some cover. However, these kind of enclosures are much harder to find on the market.
Wooden with a glass front
Great at insulating heat, gives the snake cover and should be easy enough to clean (the wood should be sealed to prevent bacteria and rot getting in). These kind of enclosures are readily available and can be found relatively cheaply. I would recommend wooden vivariums as the ideal enclosure for boas.
Note: A lock should be bought for enclosures with glass sliding doors and a secure system should be used for enclosures with mesh tops (possibly with side locks or by placing a heavy object on top (making sure it can't fall through)) because boas are very strong animals and are capable of pushing glass or mesh out of their way.
Maintaining the environment
The ambient temperature (general air temperature) should fall between 80-85 F with the cool end towards the lower end of this but not falling below 75 F. There should be a basking spot (a concentrated hot area provided by the heat source) at the hot end which should fall between 90-95 F.
A night time drop in temperature is not required but if it does occur then the ambient temperature should not be allowed to fall below 75 F.
Some basic heating options:
Heating mat -
The heat mat should cover approximately 1/3 to 1/2 the area of the vivarium floor. If using a wooden vivarium then the mat will have to go inside. Ceramic tiling or other waterproof, heat distributing, material should be fixed on top of the heat mat to prevent electrocution, should the snake knock water on top of the mat, and burning by the snake getting coiled around it.
Sealant is an appropriate method of fixing, tape is NOT. Any kind of tape can cause damage to the snake if it comes loose and gets caught.
Ceramic heater -
Most ceramic heating equipment is sold separately. The basic parts needed are:
- a ceramic bulb (150W would be an appropriate wattage for most boa vivariums)
- a ceramic bulb holder
- heat resistant wire
- a plug
- a ceramic guard (to prevent the snake coming in contact with the bulb and burning itself, or smashing the bulb and cutting itself)
The ceramic bulb attaches to the ceramic bulb holder which hangs from the roof of the vivarium. The heat resistant wire connects the bulb, through the holder, to the plug. The guard then goes over the bulb and holder, leaving around an inch clearance on each side, and is screwed into the roof of the vivarium.
Incandescent bulb -
Although I have not used an incandescent bulb myself I imagine they follow the same kind of set up: bulb, bulb holder, heat resistant wire, plug and guard. The guard is necessary here as well to prevent the snake from smashing the bulb or burning itself.
An important thing to note here is that an incandescent (or any other light emitting heat source) can only be used during the day. Having lights on during the night will disturb the snake's sleeping pattern and will lead to unnecessary stress for the animal. Therefore, if an incandescent bulb is used it will need to be used in conjunction with another heat source.
Note: Having all of these together would be overkill. Some combinations:
- Heat mat and ceramic heater
- Heat mat and incandescent bulb
- Ceramic heater
A heat source is an absolute necessity for boa keeping but at the same time, if left unchecked, it can be fatal. In order to make sure that the heat source does not reach harmful temperatures, and to maintain the necessary ambient temperature range for the boa, the heat source should be used with a thermostat.
Heat Mats - Mat/Thermostat thermostats
These thermostats operate by switching on and off the heater until the required temperature is reached. The on and off nature of these thermostats makes them inappropriate for lights but ideal for heat mats.
Ceramic heaters - Pulse proportional thermostats
These thermostats operate by sending pulses of power, which alternate in their duration to suit the temperature requirements, to the heater. The pulsing nature of these thermostats makes them especially efficient and can greatly increase the life of a ceramic heater but makes them inappropriate for lights: it would cause a strobing effect!
Incandescent bulbs - Dimming thermostats
These thermostats operate by controlling how much power is delivered to the heater. The bulb is never actually turned off but will give off different quantities of heat, depending on the required temperature. There thermostats are ideal for light emitting heaters, such as incandescent bulbs, because they are not turned on and off which stops the bulb from flickering on and off.
For boas a relative humidity measurement is needed. Measurements for relative humidity are given as a ratio: the volume of water vapour in the air at that temperature against the total volume of water vapour that the air could potentially hold at that temperature, expressed as a percentage. A reading of between 50-60% is acceptable although there is no harm in having a slightly higher humidity. The humidity should be raised to approximately 70% when the snake is in shed.
Humidity can be increased in two basic ways:
- Place the water bowl near the heat source: the increased temperature will cause some evaporation and thus increase the quantity of water vapour in the air (i.e. the humidity). However, do not place the water bowl directly on/under the heat source as snakes do not like warm water and as a result may not drink and become dehydrated.
- Spray the vivarium daily with a water spray bottle. This will increase the humidity but try not to over spray as damp environments are great breeding grounds for bacteria.
The Basic Things You Need
Once you have the correct environment set up for your snake there are some basic, superficial things your snake will need:
- two hides - one on the hot side and one on the cool side. One is needed on each side because the snake will always choose the security of a hiding place over the correct temperature. If the snake does not maintain its temperature correctly then it will get ill so it needs to be able to choose where it hides. A hide can be anything from a carved out log/bark to an artificial cave: just make sure what ever you use has been cleaned and is free from pesticides/chemicals/parasites.
- water bowl - the snake needs a water bowl big enough to submerge itself in. This can be places at either end but must not be placed directly under the heating source.
- two thermometers - one for the hot end and one for the cool end. Digital thermometers are more accurate and don't necessarily cost very much. They should be measuring the temperature on the surface of the substrate: ones with probes are most efficient at this but are not necessary).
- hygrometer - this measures the humidity. It can be placed at either end but should not be placed directly next to the heat source.
- substrate - newspaper can be used: it is the cheap option and is easily replaced - a few layers would do. Aspen is a more visually pleasing substrate though - a layer a few inches thick would do.
Decoration, such as branches and vines, would also be very much appreciated by the snake but are not necessary. The decorations, apart from making your vivarium more appealing to look at, would allowing your snake to enjoy its natural desire to climb and give the snake more cover, making it a happier/less stressed out snake. The less stressed the snake, the more likely it will feel comfortable to come out and explore its vivarium during the day. If you do decide to go with decoration though, make sure everything is securely held in place: you don't want it to come crashing down with your snake on it and possibly causing harm.
General Boa Maintenance
Boa constrictors eat rodents. Rodent meals vary in size from pinky (new born) mice to adult rats (and maybe even small rabbits in the case of the larger boa specimens). The snake should be fed prey items which are approximately the width (no larger: this can damage the snake and lead to regurgitation) of the widest part of the snakes girth. When possible the snake should be fed rats instead of mice (i.e. a rat pup rather than an adult mouse) as rats are more nutritious for the snake.
All prey items should either be pre-killed: the prey is killed right before being fed to the snake, or f/t (frozen/thawed): the prey is killed, frozen then defrosted before being fed to the snake. In the case of f/t the frozen prey item should be placed in a polythene bag (sandwich bag) then placed in room temperature/warm water until it has defrosted. The prey should not be cooked or microwaved! Snakes do not like cooked meat and even if the microwave is only used to "defrost" it will still leave some parts frozen and some parts piping hot, which could harm your snake.
Live prey should not be an option! Some people like to argue that "snakes eat live prey in the wild so there is nothing wrong with me giving them live prey, it is perfectly natural" but I'm afraid there is a flaw in this logic: your snake is not in the wild, it is in a vivarium. In the wild a snake would hunt and strike at prey when it was ready to eat and if it failed then the prey could escape and return to its hiding place. In your vivarium the snake does not choose when to eat, it has its meals placed upon it when you feel like it so what if your snake isn't in the mood to strike at and kill the live prey when you offer it - unnatural problem number 1! Secondly, your vivarium is an enclosed space: the scared rodent is placed in an unfamiliar environment and it cannot escape - unnatural problem number 2! Now rodents may look like cute, cuddly beasts to you but have you seen the teeth on them? Have you ever been bitter by one? It may not be in their nature to be agressive but if the rodent is placed in this unnatural environment and it senses it is in danger from your snake then it will fight for its life. Rodents are lighting fast when they try and they can be on your snake, biting its eyes out and tearing its scales open, before you can blink. Many snakes have had to be euthanised because of this. So to conclude: there is nothing natural about feeding your snake live prey, it is an unnecessaary act which is cruel, not only because of the unnecessary stress it causes the rodent, but because of the sheer neglect it shows towards your animal.
A boa does the majority of its growing in its first two years so for these, until the boa is around 4ft long, it should be fed once a week. After this it should be fed around once every 2 weeks and once it gets over 6ft it should be fed every 2-3 weeks as its growing will have slowed down considerably by this stage and if it is overfed it will become fat. Only one food item, of the appropriate size (no larger than the widest part of the snakes girth) should be fed at a time.
if the snake vomits up its food then it should be left for 2 weeks before feeding is attempted again. One of the snakes primary digestive tools is the bacteria it holds in its stomach and when the snake regurgitates it loses its bacteria: any attempt at feeding at this point will just lead to further regurgitation and can be fatal if the snake is not given time to regain its bacteria. The 2 weeks allows the bacteria to recolonise the snake's gut and will allow it to digest. Do not feel guilty or cruel for not feeding your snake during this time: some snakes can go over a year without eating so those 2 weeks do not make much difference in the grand scheme of things.
Snakes do not eat as often as human so it is natual to expect that they won't defecate as often. For youngers snakes with smaller prey items they may produce stool weekly where as the larger animals, eating once every 2-3 weeks, might only defecate once a month. The stool should be dark and firm: if it is runny or pale then in may be an indication that the snake is not well and it should be taken to the vet. Snakes do not "pee" in the same way that humans do. To conserve water they reabsorb water from the initial urine in their kidneys, excreting a final, rough, paste-like product. This paste (urates) should be pale, yellowish-white in colour.
When cleaning out your vivarium a reptile friendly disinfectant should be used: other commercial disinfectants may contain harmful chemicals or leave toxic residues in your vivarium. See www.livefoods.co.uk for some reptile friendly sprays.
The vivarium should be completely cleaned out roughly once a month (although you may leave it a little bit longer if necessary and if you have been thorough with your regular cleaning). All the substrate should be removed and disposed of and the vivarium and its contents should be thoroughly cleaned and disinfected and fresh substrate should be put down.
"Spot cleaning" should be done regularly: when your snake defecates the stool or urates should be removed immediately, as well as the surrounding substrate. If it should come in contact with any of the vivarium decor or walls then these should be disinfected. Snake waste should never be left lying in the vivarium: it has an extremely high bacterial content and is detrimental to the health of your snake.
The water bowl should be cleaned out at least 3 times a week (no exception can be made on this one). The snake will bathe and maybe even defecate in the water bowl and the water bowl has been shown to be one of the most bacterially colonised parts of the vivarium. It is essential for your snakes health that the water remains fresh and clean.
As a reptile grows it will shed its old skin and grow a new one underneath. The frequency of shedding depends on the size and growth rate of the boa: a young boa, during its peak growing years, will shed monthly where as an old, adult boa which has almost stopped growing may only shed a few times a year.
A few days before the snake goes into shed you will see the snakes eyes go a light blue/cloudy colour (going "in blue"). Snakes have transparent scales on their eyes and this clouding over is caused by a layer of fluid building up under these scales to help them come loose and shed. A few days, or even up to a week, later the snake will shed its skin. The shed should come off in a whole piece. Check to make sure the two, transparent eye scales have come off: if they remain on the snake they can lead to eye infection.
The main cause of an incomplete shed is low humidity. If your snake does shed incompletely then you should bathe it in lukewarm water and wrap it in a damp, lukewarm towel. Placing a damp towl in the snakes hide may also help to remove the last of the shed.
When handling your snake you should always bare in mind that, even though you might see your snake as a cute family member, it sees you as a potential threat. In the wild the young snake would be under threat from predators which would swoop down swiftly on the snake from above, probably at its head region. So taking this into consideration you should always approach your snake slowly: any swift hand movements may trigger a defensive strike, you should approach it from below or at the same level and you should aim for the snake's middle.
It is important to handle the snake often, aiming for at least 10 minutes every day, in order to get the snake used to contact with people and to "tame" it (snakes are wild animals and so will never be tame as such, but with time you will be able to interpret their actions and foresee any unwanted behaviour). That snapping little baby may look cute and forgivable but trust me, it will be quite a different matter when you have a grumpy, wild 10ft adult striking at you so it is best to get it used to people while it is still young. Baby snakes will probably be snappy to start with as, being so small, they feel particularly vulnerable - however with regular handling they should become placid.
Important times when you should NOT handle your snake:
- the first week of obtaining it - for this first week the snake should be left alone in the vivarium in order to let it settle in. I know this is hard as you are probably excited to have your new pet but any attempt at handling during this period will greatly stress your snake.
- during shed - your snake should not be handled from the time it goes in blue until the time it has fully shed. Your snake may be grumpy and handling will cause unnecessary stress.
- the 48 hours after feeding - handling while the snake still has the food lump and is digesting may cause damage to the snakes intestine, it may also cause the snake to become stressed, leading to regurgitation. Avoid doing it.